Ammonia (NH3) emissions were measured during summer from a circular area of short pasture on a slightly acid stony sandy loam soil, treated with 156 cattle urine patches of realistic size and a nitrogen (N) content of 15 g N each. Horizontal fluxes of NH3 were sampled at five heights in the centre of the treated circle. Three micrometeorological methods were used to derive the NH3 emission rate from these horizontal fluxes: the mass-budget (MB) method, the backward-Lagrangian stochastic (BLS) method, and the ZINST (height, z, independent of stability) method. Soil temperature was measured and soil samples were taken from within selected urine patches to provide pH, ammoniacal-N (NHx-N) and moisture contents as input parameters for a volatilisation model. The model describes a chain of three processes: the phase equilibrium between aqueous NHx in the soil solution and gaseous NH3 at the liquid-air interface (within the soil pores), the diffusion of gaseous NH3 in the soil layer, and the diffusion of gaseous NH3 in the atmospheric surface layer between ground and sampling height. The two diffusion processes are parameterised by resistances as functions of soil and wind flow parameters, respectively.